Heat pump water heaters are well known. For example, a United States patent of Disco, U.S. Pat. No. 4,290,275 discloses a water storage heater having a heat pump including a compressor, a condenser and an evaporator. The condenser is arranged in heat relationship with a wall of an inner hot-water container. An outer shell is spaced from and surrounds the inner container to provide an interspace, at least part of the outer shell is constituted by the evaporator. Apertures are also provided in the outer shell to provide for air circulation through the interspace.
A more recent patent of Pardo, U.S. Pat. No. 5,281,426 discloses an automatic heating and cooling tank system for heating and cooling food. The system includes an apparatus for uniformly cooking foods and rapidly cools the cooked foods to reduce spoilage. Food packages are placed on trays and the trays are inserted in a transportable rack. The rack is then loaded into a cooking tank. A pump continuously circulates hot water through a conduit from a heat exchanger to the tank to cook the food and return the hot water to the heat exchanger. A control mechanism determines and controls the temperature of the water and monitors the temperature of the food to control the length of time the heated water is applied. After the food has been cooked and pasteurized, cold water is rapidly supplied to the tank to quickly cool the cooked product. The continuous circulation of water during the heating mode provides uniform cooking with precise temperature control and the circulation during the cooling mode provides for rapid cooling so as to reduce spoilage.
A water heater/cooler is disclosed in a U.S. Patent Application Publication No. 2006/0011149 A1 of Stevens. As disclosed, a water heater having a water tank with a wall formed from a material having heat transfer properties, a tube which carries a refrigerant fluid is applied externally about the tank wall and a heat/conductive material is co-extensive with the length of the tube to allow the tube to be in heat/conductive contact with the tank wall. At least one layer of material is tightly wrapped about the tank wall and the tube.
Notwithstanding the above, it is presently believed that there is a need and a potential market for an improved water supply system in accordance with the present invention. There should be a demand because such systems enable a standard water heater to serve a dual function i.e. function as a heater in winter and a cooler in summer for water used for everyday household purposes. The system in accordance with the present invention provides an inexpensive and practical way to cool water in desert like areas in the summer months instead of cooling a larger water tank that may be placed on the roof of a house. In winter, the same system may be used to provide heated water.